Documentation: gpio: Move GPIO mapping documentation to driver-api (6960341a) · Commits · e / devices / android_kernel_fairphone_FP5

Documentation/gpio/board.txt→Documentation/driver-api/gpio/board.rst

+21 −18

Original line number	Diff line number	Diff line
		=============
		GPIO Mappings
		=============

		@@ -23,7 +24,7 @@ device tree bindings for your controller.

		GPIOs mappings are defined in the consumer device's node, in a property named
		<function>-gpios, where <function> is the function the driver will request
		through gpiod_get(). For example:
		through gpiod_get(). For example::

		foo_device {
		compatible = "acme,foo";
		@@ -40,7 +41,7 @@ it but are only supported for compatibility reasons and should not be used for
		newer bindings since it has been deprecated.

		This property will make GPIOs 15, 16 and 17 available to the driver under the
		"led" function, and GPIO 1 as the "power" GPIO:
		"led" function, and GPIO 1 as the "power" GPIO::

		struct gpio_desc red, green, blue, power;

		@@ -60,13 +61,13 @@ looked up by the gpiod functions internally) used in the device tree. With above

		Internally, the GPIO subsystem prefixes the GPIO suffix ("gpios" or "gpio")
		with the string passed in con_id to get the resulting string
		(snprintf(... "%s-%s", con_id, gpio_suffixes[]).
		(``snprintf(... "%s-%s", con_id, gpio_suffixes[]``).

		ACPI
		----
		ACPI also supports function names for GPIOs in a similar fashion to DT.
		The above DT example can be converted to an equivalent ACPI description
		with the help of _DSD (Device Specific Data), introduced in ACPI 5.1:
		with the help of _DSD (Device Specific Data), introduced in ACPI 5.1::

		Device (FOO) {
		Name (_CRS, ResourceTemplate () {
		@@ -105,12 +106,12 @@ Documentation/acpi/gpio-properties.txt.
		Platform Data
		-------------
		Finally, GPIOs can be bound to devices and functions using platform data. Board
		files that desire to do so need to include the following header:
		files that desire to do so need to include the following header::

		#include <linux/gpio/machine.h>

		GPIOs are mapped by the means of tables of lookups, containing instances of the
		gpiod_lookup structure. Two macros are defined to help declaring such mappings:
		gpiod_lookup structure. Two macros are defined to help declaring such mappings::

		GPIO_LOOKUP(chip_label, chip_hwnum, con_id, flags)
		GPIO_LOOKUP_IDX(chip_label, chip_hwnum, con_id, idx, flags)
		@@ -141,6 +142,8 @@ end. The 'dev_id' field of the table is the identifier of the device that will
		make use of these GPIOs. It can be NULL, in which case it will be matched for
		calls to gpiod_get() with a NULL device.

		.. code-block:: c

		struct gpiod_lookup_table gpios_table = {
		.dev_id = "foo.0",
		.table = {
		@@ -152,11 +155,11 @@ struct gpiod_lookup_table gpios_table = {
		},
		};

		And the table can be added by the board code as follows:
		And the table can be added by the board code as follows::

		gpiod_add_lookup_table(&gpios_table);

		The driver controlling "foo.0" will then be able to obtain its GPIOs as follows:
		The driver controlling "foo.0" will then be able to obtain its GPIOs as follows::

		struct gpio_desc red, green, blue, power;

Documentation/driver-api/gpio/index.rst

+1 −0

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		@@ -10,6 +10,7 @@ Contents:
		intro
		driver
		consumer
		board
		legacy

		Core

Documentation/gpio/00-INDEX

+0 −2

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		@@ -3,7 +3,5 @@
		drivers-on-gpio.txt:
		- Drivers in other subsystems that can use GPIO to provide more
		complex functionality.
		board.txt
		- How to assign GPIOs to a consumer device and a function
		sysfs.txt
		- Information about the GPIO sysfs interface